Shutter wing for airships



Nov. 1, 1932. F. c. KRUMMEL SHUTTER WING FOR AIRSHIPS Filed Dec. 3. 1930 3 Sheets-Sheet l 0 R) & 8 5 f N w b w a a n H g: 1 *1 00% g: N F f m \e m w P 8 2 w I Nov. 1, 1932.

F. C KRUMMEL SHUTTER WING FOR AIRSHIPS Fild Dec. 3, 1930 3 Sheets-Sheet 2 NOV. 1, 1932. c KRUMMEL 1,885,733

SHUTTER WING FOR AIRSHIPS Filed Dec. 3, 1930 3 Sheets-Sheet 3 Patented Nov. 1, 1932 UNITED STATES FREDERIC CHARLES KRUMMEL, OF BRIGHTWATERS, NEW YORK SHUTTER WING FOR AIRSHIPS Application filed December 3, 1930.

This invent on relates to the construction of wings for airships and more particularly concerns a wing having a divided upper surface through which air may be passed from beneath the wing to above tht wing, to two devices associated therewith for controlling the passage of this air.

It is well known that airship wings have a peculiar characteristic in that as the angle of attack increases, the lift increases at a ratio depending upon the shape of the wing. This increase continues up to a certain point which may be called the critical angle, beyond which the air no longer flows smooth- :t ly as a sheet over the upper surface of the wing, but instead forms Whirlpools or eddies above and at the rear of the wing. This causes a diminished lift, and hence, owing to the Whirlpools and eddies, the critical 2c angle is sometimes called the burble point. Therefore, if an air foil in its progress through the air, is turned on a horizontal axis until it is beyond the critical angle or burble point, the effective lift decreases, and the plane reaches a point of instability at which there is danger of stalling, or passage into a slip of some nature or another. Also, the loss of lift, if near the ground, may result in a crash before the plane can again be brought into a position at which the lift overcomes the gravitational attraction upon the plane.

This condition is particularly dangerous on taking off or alighting, since it is customary, and often necessary, to lift the plane to a considerable height to clear the bounds of the flying field, even though the normal air speed has not yet been attained; while in alighting, it is desirable to have the landing speed as low as possible and hence to have the angle of attack as high as posible to gain a maximum lift and hence a gentle contact with the ground as the plane slowly approaches it.

According to the present invention, the

' wing is provided with at least one shutter whereby air may be passed from beneath the wing to above the wing to mingle with the air flowing over the upper surface of the wing and hence to delay the burble point or increase the angle of presentation of the wing Serial N0. 499,767.

to the air at which the burble point occurs. Thus, the burble point is delayed and it is possible to fly at a much higher angle of attack without danger of loss of lift by the formation of eddies and whirls.

Another feature of the present invention is the provision of means for controlling the operation of the shutter, either automatically, mechanically or manually, whereby to regulate the effective lift and also to control the permissible angle of attack.

A further feature of the invention is the provision of means whereby the shutter may be maintained in a closed position and out of action during normal flight, thus affording a smooth upper surface to the wing, but may be opened or brought into action quickly upon the occurrence of an emergency.

\Vith these and other objects in view, as will appear in the course of the following specification and claims, several forms of the construction are set forth on the accompanying drawings, in which:

Fig. 1 is a perspective view showing diagrammatically, the association of a control system with wings having a plurality of shutters.

Fig. 2 is a detail View of Fig. 1.

Fig. 3 is a vertical sectional view through a wing taken in the line of flight, showing the mounting and character of a plurality of shutters.

Fig. 4: is a bottom view of a portion of the wing of Fig. 3.

Fig. 5 is a view corresponding to Fig. 3, but on a slightly smaller scale and showing a modified form of construction.

Fig. 6 is a view similar to Fig. 5, but showing a form of construction of the lower wing surface corresponding to that of Fig. 1.

Fig. 7 is a bottom view of Fig. 6.

Fig. 8 is a perspective View of a manner of connecting the operating cables for actuation from the main power plant of the airship.

In the drawings, the wings W, W, in Fig. 1, are illustrated as having upper and lower covering surfaces, the lower covering surface of each wing being provided with a series of slots 10 through which air may enter the interior of the wing from beneath the lower Ice surface thereof. The upper surface of each wing comprises a plurality of independent shutters orpanels 11, as will be described more in detail hereinafter, and which are individually susceptible of movement whereby air may pass from within the wing to a point above the next following shutter.

In Fig. 1, the rear ed e of the wing is formed of an aileron mem er 12, which may be controlled in any desired manner (not shown) for the usual purposes.

Within access of the aviator there is provided a hand lever 13 which is pivotally mounted on the airship frame and is provided with a sector 14 and a latch 15 for controlling the position of this lever. Connected to this lever are two cables 16, each passing to its articular win and travelling over the guide pulleys 17 xed in the wing structure as well as over the driving pulley 18 which is revolubly mounted on a crank 19 of a shaft 20 which is driven through a reducing train, illustrated schematically at 21, from an air propeller 22 which may be located 1n the slip stream from the driving propellers of the airship.

The hand levers 23 are likewise located within easy reach of the aviator and each is respectively connected by the link and lever system, with a suitable clutch member (not shown), associated with the corresponding reducing gear 21.

In Fig. 3, the individual shutter members 11a, 11b, 11c, 11d, are mounted by pivots 30 between ribs 31 of the wing structure, which in turn are supported by the spars 32 thereof. The lower surface of the wing is provided with a plurality of openings 10a, preferably with flanged edges for greater strength, these openings being shown in Fig. 4 as comprising separated slots having their greater dimension in the line of flight. Likewise, pivotally mounted on the rib 31 of Fig. 3, are a plurality of crank levers 35 having slotted arms to receive the pins 36 secured to the shutters 11a, 11b, 11c, 11d, whereby a movement of the crank levers 35 is accomplished by a corresponding movement of the respective shutters. The other arms of the crank levers 35 are joined together by links 37 so that the levers are moved together. Return springs 38 which may be of wire or rubber, are connected between the link and lever system and the wing frame whereby to move a crank lever in a counter-clockwise manner, and thus to open the respective shuttor, and are preferably provided with the adjusting devices, comprising the eyebolts 38a and nuts 38?). The cable 16 after passing a guide pulley 17, having a substantially vertical axis, is connected to the link and lever system and operates to hold the shutters in a closed posit-ion or to move them toward such a position.

In Fig. 5, the lower covering surface of the wing is rovided with a plurality of openings 1012, w ereby air may enter the interior of the wing. The shutter members 41a, 41b, 41c, 41d are pivotally mounted as before by pivots in the wing structure.

Each shutter has a crank arm 42 extending from its pivot mounting. The crank arms 42 of the three rearward shutters are connected by links 43, while the crank arm 42 of the forward shutter is connected to a crank lever 44, pivotally mounted on the wing structure and it is connected by a link 45 to the links 43. The shutter cable 16 is connected to the link system as before, while a return spring 46 tends to move the shutters toward the open position.

In Figs. 6 and 7 an arrangement of the sh utters identical with that of Fig. 5 is shown, but the lower covering surface of the wing is illustrated as having the longitudinal slots 10 extending substantially the entire distance between ribs 316, one of which is shown, and having the inwardly bent reinforcing flanges 10m adjacent thereto.

In Fig. 8 is shown a modified manner of operating the cables, in which the main power plant 50 drives the propeller 51 for the movement of the ship through the air and is also provided with a shaft 52 having a clutch 53, operable by ratchet 54 thereon. A worm 55 is connected in extension of the free clutch arrangement. This worm 55 drives a worm wheel 56 on a shaft 57 having a symmetrically formed cam 58 thereon. Two cam levers 59 are mounted on the airship frame with rollers 60 operating as cam followers. These levers are connected at their outward ends to cables 16a which pass over the guide pulleys 17 and are connected, for example, by the crank 42 of Fig. 5 to a shutter 410.

The spring 46 is diagrammatically illustrated as urging the shutter toward an open position and the corresponding cam lever 59 to press its follower (30 against the cam 58.

In operation, during normal flight, with the structure of Fig. 1, the levers 23 are moved until the propellers 22 do not drive the shaft 20, and the pulley 18 is at its greater distance above the shaft 20. The lever 15 is then operated to take up any slack in the cables 16 and thus to close the shutters and hold them closed. In other Words, during normal flight, the wing operates as a closed circuit wing. Upon landing or upon the plane becoming involved in a slip owing to the formation of eddies above the upper covering surface of the wings, or in any other condition where it is essential that the burble point be delayed, the levers 23 of one or both wings are moved so that the revolution of the propellers 22 cause movements of the corresponding shafts 20 and therewith a relative upward and downward movement of the driving pulleys, so that slack is afforded to the cables 16 intermittently and cyclically during the revolution of the shaft 20. The spring 38 of Fig. 3, for example, then operates to draw the shutter open at the slack periods, being assisted in this by the reduced pressure beneath the lower covering surface and transmitted. through the openings 10, 100, 106, into the interior of the respective wing construction.

The shutters therefore are free to open so long as there is slack at 16, but are intermittently drawn down into closed position during the revolution of the shaft 20. Thereby the wing alternately operates as a wing having a solid upper covermg and as a wing having a plurality of panels forming the upper covering, between which air may pass from beneath this surface to above it.

If an emergency arises suddenly, the aviator can release the latch 15 so that the cable 16 is afforded full slack, and thus an incipient stall by lack of lift may be counteracted: or a better landing angle for the particular speed afi'orded. Further the lever 15 may be adjusted to permit a slight escape of air between the shutters if so desired, whether the driving pulleys 18 are operated or not.

In the type of construction shown in Fig. 8, the aviator, by connecting the parts of the clutch 53 by operation of the hand lever 54,

can cause the cam levers 59 to be moved with I a resultant intermittent movement of the .cables 16a and thus a successional opening and closing of the shutters: while by controlling the position of the cam by determining the point of disengagement of the clutch 53, he can operate the airship with the shutters open to a greater or lesser extent.

It is also possible to attain an automatic operation of the shutters with the constructions of the several figures under certain conditions of travel. When the airplane is travelling at high speed and at a low angle of attack, the pressure upon the upper surface of the respective shutters, by reason of their inter-connecting linkage, is so great that the shutters cannot open. If the airplane is then controlled so that a greater angle of attack is employed, the airpressure is lessened upon the upper surface, and hence the differential of pressures prevailing will cause a slight opening of the shutters and an automatic delay of the burble point;

In such cases of automatic operation, the adjustment 38a, 38b, for the springs 38, in Fig. 3, or the similar adjustment for the springs 46 in Figs. 5, 6 and 8, are so regulated that the shutter will open at the desired angle of incidence or attack. For this purpose, it is preferred that the springs be so adjusted that they will very nearly neutralize the effect of the weight of the shutters and hence the strucure is easily actuated by the increase of suction upon the upper surface by reason of increase of the angle of attack.

It is obvious that the invention is not limited to the forms of construction shown, but that it may be modified in many ways w1th1n the scope of the appended clalms.

I claim:

1. An airship wing having a shutter providingapart of its upper surface, said shutter being movable from a POSltlOH III WlllCh the passage of air through the wlng from beneath the shutter to above the shutter 1s prevented to a position in which air may pass through the wing, and means to move the shutter periodically from one position to the other.

2. An airship including a power plant, and a wing, said wing having a plurality of shutters for providing at least a part of the upper surface of the wing, crank and link connections between the shutters whereby they may be moved simultaneously, a cable attached to said connections, means for opening the shutters, and means of the airship for alternately pulling and releasing the cable whereby to effect acyclic opening and closing of the shutters.

3. An airship including a power plant and wings, at least one of said wings having a shutter which may move from aposition in which the passage of air through the wing from beneath the shutter to above the shutter is prevented to a position in which air' may operated by the power plant pass through the wing, a cam driven from said engine, a cam follower, and a cable for connecting said cam follower and said shutter whereby said engine may periodically move said shutter into a closed position and thereafter permit the same to open.

4. An airship as in claim 3, including means for holding the cam stationary in any position.

5. An airship including apower plant and right and left wings, each of said wings including a shutter which may move from a position in which the passage of air through the wing from beneath the shutter to above the shutter is prevented to a position in which air may pass through the wing, a symmetrical rotatable cam driven by the power plant, a pair of cam followers cooperating with said cam, and means for connecting said followers to said shutters whereby the shutters are opened and closed intermittently as said cam rotates.

6. An airship including right and left wings, each of said wings having a shutter which may move from a position in which the passage of air through the wing from beneath the shutter to above the shutter is prevented to a position in which air may pass through the wing, cables connected to the shutters and to a manually operable tension adjusting device, and means operated by the air stream incident to the movement of the airship for taking up the slack in said cables independently of said manual device.

An airship as in claim 6 in which said means includes devices for takin up the slack in the cables connected to the right and left win shutters, and manually operable indepen ent devices are provided for preventing the operation of said takeup devices.

8. An airship as in claim 6 in which said tension adjusting device is provided with means for holding the same in adjusted position and permitting the same to be quickly moved to a position affording slack to said cable independently of the position of said air operated means, whereby the shutters may be permitted to open.

9. An airship having right and left wings each having a shutter providing a part of the upper wing surface, each said shutter being movable from a closed position in which the passage of air from beneath the shutter to above the shutter is prevented to an open position in which air may pass the shutter from beneath the surface, power means for periodically opening and closing said shutters, and manually operated means for controlling the operation of said power means.

10. An airship as in claim 9, in which independent manually operated means are provided for controlling the operation of said power means upon the shutter in each wing.-

11. An airship as in claim 9, in which manually operable devices are provided for quickly releasing the shutters for movement into open position regardless of the condition of operation of said power means.

12. An airship having right and left wings each having a shutter providing a part of the upper wing surface, each said shutter being movable from a closed position in which the passage of air from beneath the shutter to above the shutter is prevented to an open position in which air from beneaththe surface may pass the shutter, means operable by the air stream while the airship is in flight and connected to move said shutters to closed position, and further manually controlled means for quickly releasing the shutters and permitting them to open regardless of the condition of operation of said shutter moving means.

In testimony whereof, I afiix my signature.

FREDERIC CHARLES KRUMMEL. 

